Concept
Controlled-environment agriculture (CEA) -- which includes indoor agriculture (IA) and vertical farming—is a technology-based approach toward food production. The aim of CEA is to provide protection from the outdoor elements and maintain optimal growing conditions throughout the development of the crop. Production takes place within an enclosed growing structure such as a greenhouse or plant factory. Plants are often grown in a soilless medium in order to supply the proper amounts of water and nutrients to the root zone as well as supplemental lighting to ensure a sufficient daily light integral. CEA optimizes the use of resources such as water, energy, space, capital and labor. CEA technologies include hydroponics, aeroponics, aquaculture, and aquaponics. Different techniques are available for growing food in controlled environment agriculture. Currently, the greenhouse industry is the largest component of the CEA industry but another quickly growing segment is the vertical farming industry. Controlled Environment Agriculture has the ability to produce crops all year round, with the possibility of increased yield by adjusting the amount of carbon and nutrients the plants receive (Benke et al). In consideration to urban agriculture, CEA can exist inside repurposed structures, built to purpose structures or in basements and subterranean spaces. The trend is increasingly growing into alternative food networks, as entrepreneurs and households seek to meet the growing demand for fresh food products. Controllable variables: Environmental: Temperature (air, nutrient solution, root-zone, leaf) Relative Humidity (%RH) Carbon dioxide (CO2) Light (intensity, spectrum, duration and intervals) Cultural: Water Quality Nutrient concentration (PPM of Nitrogen, Potassium, Phosphorus, etc) Nutrient pH (acidity) Cropping duration and density Cultivar Pest controls CEA facilities can range from fully 100% environmentally controlled enclosed closed loop systems, to automated glasshouses with computer controls for watering, lighting and ventilation.